Constant delivery variable pressure pump



Jan. 1, 1957 e. H. HUFFERD CONSTANT DELIVERY VARIABLE PRESSURE PUMPFiled March 2, 1953 2 Sheets-Sheet 1 fi'TS/EJYEEZ georye HHaff 36 y ama; w wz y Jan. 1, 1957 G. H. HUFFERD.

CONSTANT DELIVERY VARIABLE PRESSURE PUMP Filed March 2, 1953 2Sheets-Sheet 2 lEYYEZT/ZTQP yeojye HHa erJ U ited States Pate CQNSTANTDELIVER-Y VARIABLE: PRESSURE PUMP! George. H: Herrera; Shaker Heights,Ohio I Application Mal-ch 2; 1953, SerialiNoa 339 640;

13 Cliiiins. (c1; lot-120) This invention relates generally to a pumping,apparatus capable of delivering a constant volume of fluid withoutcavitation and without regard to wide variation in'delivery pressure.

,M ore specifically, the present invention relatesto a variablepressure, Constant delivery, guided vane pump wherein at rotor providingan. annular. row'of circumferentiallyjspaced slots carriesacorrtespondi'ngplurality of. vanes :slidably supported" in therespective slots for en'- ga'gemenflwi-th: the cylindrical pumpingchamber bore of a" regulating block'supported' in. a casing for movementtransversely ofthe; rotor axis to adjust the: relative eccentricity' ofthe pumping; chamber bore; and therotor, the'jadjustment'of the block.being effected" in" response to" variationsdn' the effectivedifferential of a pressure drop..across an orifice provided'in'a flowpath through the pump-and including;the' inlet'and -the outletof "the"pump.

Althougllf-tlfeprinciples ofthe present invention are of generalutility," a" pump embodying the features of the present invention findsa particularlyuseful application in.- connection" m'th" supplyingfluid." under "'pressure' to a i'sdonebeforethe"fluidcarr'returnto'the'reservoir: Since resistance isencounteredin thisprocess; pressure'is immediately established *andthework done;

since greatf variations are encountered in the*rota'- tional-speed ofan-engine driven-pump; i-t'is highly desirahl e-thatprovision be madefor asource of -'illlidenergy in" a-hydtaulic system which" will 'beconstant in delivery within rather narrow limits; Wide variation influid-delivery-in'an open centersystem' resultsin a'lossofsensitivit'y-in the actuating valve or in overheating of the fluidwith consequent loss of "energy;

In-the pumps heretofore provided; provision is'sometimes'madeto"starve"the' inlet'of the pump in'order to control the flow. In aconstant delivery pumpthis practice'produces' cavitation withaccompanying nois'e resulting from" the hammer" of the fluid on themetal components of the pump" as the fluid onthe*-de1ivery side of'the'pump 'rushes to fill the vacuum of displacement causedbythe'inletstarvation.

According to the principles of the present invention, a variabledeliverypurnp is provided in "which the inleris con-trolled; however,instead of utilizin static pressure variables to control thepump; thepump COBtIOlllHEQPIGS- sures are determined andestablishedxbwtheiflovn'of the pumping-=1 fiuidi throughw an'r orificewands that differential variablescon ;.va riaitions,zrinzt pressure :dropacrossttheaorifice are utilized for control purposes.

It will: be appreciated thatv pump, control' whichv is. eftested inresponse. to pressure drop variations will be independent ot'aetualstatic pressure values and; accord.- ingly, the pressure drop controleffected in accordance withtheprinciples of'the present invention willbeaccurate even through the pump, is required'to be used"at differentaltitudes.-

It is an ob'jectof the presentinvention, therefore, to provide aconstant delivery variable pressure pump which overcomes thedeficiencies of the prior art structures heretofore providedi Another.objectof theipresent'invention is to-provide a pump wherein volume'maybe regulated without regard" to. static" pressure values;

A further objectof the presenrinvention is to utilize a pump controlsystem'- wherein" the pump controlling pressuresare'determinedandestablishedb'Ythe flow of fluid through an orifice'and wherein the-controllingvariahleconsists' of the" pressure drop established across"the orifice.

Yet another object ofth'e present inventionis'toprovide a; pump controlwhich is independent of "altitude li'initations;

Many otherfatures, advantages and" addi tional objects ofthepresentinventio will hecomenianifest tothose versed in theartupon=mak in-g 'reference to the-detailed description-'whichi followsand" the accompany sheets of drawings inewhich preferredstructuralembodiments' of pumps constructed in accordance withtheprinciples of the present invention are shown by way of illustrativeexample"only On' the drawings:

Fig-ure l is =a cross sectional View" M a-"constant delivery variablepressure pump provided in accordance with the principles ofithe presentinvention;

Figure 2 is a cross-seetiona-l view ofa1modified embodimentg' Figure? 3?is .arcross-sectiona'l :view'takem onwaplane generally transverseeofFigures-4 :and 5 and illustrating addivti-onal details of'conStru'ctionotbothuheFigure 4' and-FigureSrpumpsgr.

Figure: 4* is' a cross-sectional .view ofianother' embodimentwprovidedin accordance with thefprineiples of" the present: invention;

Figure Sris a cross sectio'nalr-view' ofta pumprgenerally similar;toathat shown 1 in-- Figure: 4"bllltl embodying; an:.-alternativemodification 1 in :accordance with" the; principles of rthe: presentinvention; rand I Figure 6 is an enlargedfragmentary;crossesectionabfietw showing. additional: details 1 ofconstruction ofi'thecontrol i valve: providedim the :embodiment of:Figure :41

Asshown onlthe drawings;

Inlorder tot illustrate the: applications of the-principles of thepresentr invention, there iswshown" in the drawings a; guided-vane typepump: wherein 'a single rotori revolves inn a: case. The pumping;element" consists of multiple blades sliding ini slots provided by therotorand I the'rimpeller and the case are eccentricwithrrespecttoloneifanother. CentrifugaL force oripressure" maintainsthe router end of theblades incontact witht-thehcasingzborei and thecapacity of the pump isregulatedibye adjustingvtheprelative eccentricityof thetirnpeller 'and the. case. Although various modified' embodimentstWillJbC described: herein;- similar reference numerals will beappliedwherever possible in the: interest Ofr'ClfiI'ltY-iz.

Asrshown. in Figure :1, a-constant deliveryvariablepressure pump isindicatedt generally by the-:referencewharacter 10 and comprises aregulator blockell 'havi-ngtflat sides-indicated=at IZ-iand'13.:respectively; .& reactive pressure face 14 is provided Ion '1 oneend of: the block-l 11--and a second reactive-= pressure: face: 164 isprovidedw one. the

,oppositeend of the-tbloclulls Between the reactive pressure faces 14and 16 is forme a cylindrical pumping chamber bore indicated at 17, thebore 17 being provided with an annular groove or grooves ondiametrically opposite sides thereof forming an inlet relief 18 and anoutlet relief 19.

A casing 20 is provided for the pump and includes a hollow cavitybounded by flat internal walls mating with the flat sides of the block11 to slidably support the block 11 for movement transversely of theaxis of the pumping chamber bore 17. More specifically, the casingprovides a first flat internal wall 21 slidably engaging the fiat side12 and a second flat internal wall 22 slidably engaging the flat side13.

The reactive pressure face 14 is spaced from a casing wall 23 and thereactive pressure face 16 is spaced from a casing wall 24 to provide apressure control chamber 26 and a pressure control chamber 27,respectively, which pressure control chambers 26 and 27 are located onopposite sides of the axis of the pump chamber bore 17.

A boss 28 extends into the pressure control chamber 27 from the wall 24and forms a stop to engage the reactive pressure face 16 of the block11.

A boss 29 extends into the pressure control chamber 26 from the wall 23and forms a stop to engage the reactive pressure face 14 of the block11.

As shown in Figure 3, the casing 20 is provided with a front member 30and a back member 31 which are assembled together by a plurality offasteners 32.

Referring to Figure 3 in connection with Figure 1, the pump rotor isshown as including a rotor shaft 33 having a radially outwardlyextending body portion 34 and an annular axially extending ring 36providing an annular roll of circumferentially spaced slots 37 eachreceiving a vane 38.

A floating tubular abutment 39 engages the radial innermost ends of thevane 38, the tubular abutment 39 having an outside diameter smaller thanthe inside diameter of the annular ring 36.

The radial outermost ends of the vane 38 engage the walls of the pumpingchamber bore 17.

Although the positioning stops 29 and 28 prescribe the limits ofadjustment of the regulating block 11 and hence the capacity limits ofthe pump, a continuous biasing means is provided between the regulatingblock 11 and the casing 20 in order to adjust the relative eccentricityof the pump chamber bore 17 and the rotor ring 36 so as to maintain aminimum eccentric pumping position. In the preferred embodiment hereindescribed, the continuous biasing means takes the form of a coil spring40 having one end bottomed against the reactive pressure face 14 andhaving the other end bottomed against a plug 41 threaded into the openend of an aperture 42 extending through the boss 29.

A fluid flow path is provided through the pump 10 and in the embodimentof Figure l, the fluid flow path includes an inlet 43 extending througha boss 44 providing a threaded aperture 46 adapted to receive inthreaded assembly a suitable conduit means (not shown).

The flow path further includes an outlet 47 extending through a boss 48having a threaded aperture 49 adapted to receive in threaded assemblytherewith suitable conduit means (not shown).

As indicated in Figure l, the casing 20 is provided with an outletrelief 55 formed as a recess in the wall 21.

In accordance with the principles of the present invention, a passageway50 extends through the block 11 between the pressure control chamber 26and the pressure control chamber 27.

The block 11 is further provided with a passageway 51 extending betweenthe pressure control chamber 26 and the pumping chamber bore 27, thepassageway 51 intersecting the inlet relief 18.

An outlet passageway 52 is formed in the block 11 intersecting theoutlet relief 19 formed in the walls of the pumping chamber bore 17 andcommunicating with the outlet relief 55 and the outlet 47 formed in thecasing 20.

An orifice 53 of predetermined size is located in the passageway 50 andis utilized to establish a discrete pressure drop in the flow paththrough the pump 10. More specifically, the restriction provided by theorifice 53 aflords a pressure differential acting on the respectivereactive pressure faces 14 and 16 to regulate the volumetric capacity ofthe pump in response to the pressure drop variations across the orifice53.

In other words, because the orifice 53 provides a restriction in theflow path between the pressure control chamber 27 communicating withinlet 43 and the pressure control chamber 26 communicated to the inletside of the pumping chamber bore 17, there will be a pressuredifferential between the pressure control chamber 27 and the pressurecontrol chamber 26 which will tend to actuate the regulator block 11against the continuous biasing force exerted by the coil spring 40 sothat the relative eccentricity of the pumping chamber bore 17 and therotor ring 36 will be reduced.

By selecting the spring 40 to exert a predetermined continuous biasingforce, and by properly proportioning the size of the restrictionafforded by the orifice 53, the volume flow of the pump 10 will beclosely controlled within desired limits.

In the embodiment of Figure 1, the maximum pressure drop across theorifice 53 will be atmospheric. In the embodiment of Figure 2, thestructure and function of the pump is similar to that described inconnection with the embodiment of Figure 1, however, the pressure dropis produced by pressurized discharged fluid flowing through an orificelocated on the outlet side of the pump, thereby affording greaterflexibility in selecting a desirable pressure drop for control purposes.

In the embodiment of Figure 2, an inlet is provided as at 56 extendingthrough a boss 57 having a threaded aperture 58 adapted to be connectedto suitable conduit means.

The regulating block 11a is formed with an inlet passage 59communicating the inlet 56 with the inlet relief 18a formed in the wallsof the pumping chamber bore 17a.

An outlet 60 extends through a boss 61 having a threaded aperture 62adapted to be connected to suitable conduit means.

A passageway 63 is formed in the regulating block 11a and extendsbetween the pressure control chamber 26a and the pressure controlchamber 2711.

An outlet passage 64 communicates the pumping chamber bore 17a with thepressure control chamber 27a, the passage 64 intersecting the outletrelief 19a formed in the walls of the pumping chamber bore 17a.

An orifice 66 providing a restriction of predetermined size is locatedin the passage 63 and affords a pressure differential between thepressure control chamber 27a and the pressure control chamber 26a whichis effective to act on the respective reactive pressure faces 14a and16a on the block 11a, thereby to regulate the relative eccentricity ofthe pumping chamber bore 17a and the annular ring 36 of the rotor inresponse to the pressure drop variations across the orifice 66.

It will be appreciated that any desirable pressure drop may beeffectively utilized in connection with the embodiment of Figure 2 andthe pressure drop selected will not be affected by variations ofpressure due to altitude changes. Moreover, it will be appreciated thatany pressure variations in the outlet line due to variations in demandwill be instantly transmitted through the regulating block 11a and willnot detrimentally affect the eccentricity control provided in accordancewith the principles of the present invention since the regulation of theblock 11a is effected by the pressure differential afforded by thepressure droy across the orifice 66 and not by a variable staticpressure.

In the embodiments of Figures 1 and 2, the pressure difierentialafforded by the pressure drop across an oriarr-e946 a fice in the, fluidflow path through the pump is communicated to the eccentricity.regulating means by passageways formed in the regulating block, perse.It willbe recognized that those versed in the art thatthe principles ofthe present invention can also be applied to a positivedis} placementpump by means of a separate valving mechanism constructed to, respond topressures on opposite sides of a control orifice.

In the embodiment of Figure 4, a,modified. embodiment of a pumpconstructed in accordance with the principles of the present inventionutilizes such a. separatev valving. mechanism.

In the embodiment of Figure4, no biasing spring is utilized between thecasing.20 and the regulating block 11b, the stop 2%. extending into thepressure control chamber 261 and engageable with the reactive pressureface 14b to prevent the relative eccentricity of thelpumpingchamber-bore 17b and the annular ring 36 of the rotor from ever becomingzero. Thus, the pump. is always ready to deliver fluid upon rotation, ofthe rotor. Preferably the stop 29b is so-locatedas to determine the stopposition at which the highest possible rotational speed of the rotorwilloccur; correspondingly, the position determined" by the stop 28bwill correspond: to an idling position.

In theembodiment of Figure 4, an outlet 70 is provided irr the flow pathextendingthrough a boss 71 having a threaded aperture 72 adapted to beconnectedto a suitable conduit'means. The outlet 70 communicates with anoutlet passageway 73 formed-in the regulating block 11b, an inletpassageway 74 being provided in the regulating block 11b on the oppositeside thereof;

The casing in the Figure 4 embodiment is provided with anenlarged'portion 7'6-having'an inlet assagewa 77" extending therethroughand opening at one end in registry with the inlet passage 74 formed inthe regulating block 11b. The other end of theinlet passage 77 isthreaded-as at 78 and is adapted to be connected to a suitable conduitmeans.

Along the length of the inlet passageway- 77 is provided'a cylindricalbore 79 forming a-housing forthe separate valving mechanism indicatedgenerally at'80u A movable valve spool 81 of cylindrical'configurationis axially reciprocablein the cylindrical-bore 79 -and' is. normallybiased toward a so called neutral position bysa continuous biasing meanstaking the form of a coil; spring 82'." The spring- 82is bottomedatoneend -in the casing 20 and has its opposite end engaging the valvespoolt8'1 to urge the valve spoo18'1 in-upstrearn direction. Axletainerring 83"is-seated inan annular recess 84l'provided along thelength ofthe. inlet passage 77 to limit :upstream movement of the valve spool 81.

A tubular bore-86 extends through the valve :spoolrSl and 'isinterruptedby a radially inwardly. extendinglribt which is medially located andwhich provides :an; .orifice 88providinga restriction of predetermined,size-in; the flow path through the pump.

On the external peripheral surface of thevalveo spool 81 a' pair ofspaced apart annular groovesarerproyided a first groove 90communicatingwiththe inlet, passage 177 onthe upstream side. of the.orifice 8-8 througha. suitable opening 91; and a second groove9z'communicating with the inlet passage 81downstream of-the orifice .88'through a suitable: opening 93.

The cylindrical'bore 79.-is also providedwith-spaced apart annulargrooves formingpassageways communieating-with the pressure control;chambers 26bw-and 27b and controlled. by movement of the valve spool.81.- A first annular groove. 96 is located'adjacent the-upstreamend-Lot the: cylindrical bore 79 and spaced .away there from indownstream direction a'secondannulangroove 97"is provided. Bothoftheannular grooves 96 and97 communicate with the pressure controlchamber;.26b

through: apassageway 98' formed-in the enlarged-portion 76'ofthecasingZl);

A medial annular groove 99 is provided 1n the cylin- 'regulating'block11b due to leakage will'becorrected as dnicabbore: 79 between thegrooves 96" and 9-7 andcommunicates with the pressure control chamber27b by means of a; passageway 100 formediir the enlargedfportion 76.0fthecasing 20.

By virtue of the; spacing relationship between the grooves 96, 97' and99,- there is provided therebetween spaced lands'indicated at 101; and"102 which cooperate with the annulargrooves and 92 formed in" theperipheral surface or the valve spool 81. In like manher,- the valvespool- 81 provides spaced lands 103, 104 and 106; respectively whichcooperate with the grooves 96; 97 and. 4

In'operation, the orifices 88 will pass ratedfiow through the inletpassage 77 at a predeterminedpressure drop, the spring 82' normallymaintaining the valve spool 81 inan axial neutralf positionin thecylindrical bore 7 9 corresponding to; that'position resulting whenacorrect pressure drop across the orifice- 88 1's achieved-.-

' Should'the rotational speedof thepump change, the pressure in thefirst inlet passage 77- will also change, thereby varying the pressuredifferential or pressure drop across the orifice 88. 7

Since the spool 81 is movablymounted and-is physically interposed in theflow path so that the flow of fluid through the inlet passage 7 7-1 will1 tend to move the spool 8 lagainst the biasof the spring-82, itwill'b'e manifest that'a change in the pressurie-dropacross the orifice88 will result in a movement off the valve spool 81 and, consequently,the pressure control---chambers-26b-andf2712 willbe" selectivelysubjected to the pressures in the tubular bore 86 oftl iemovable valvespool 81 on either the upstream side of'the orifice 88 Off thedownstream side of the orifice" 88 thus producing the same pressure dropbetween the pressure control chamhers Z'Gb andZIb andcommunicating theeffective differential of the pressure drop to the-=reactivepressurefaces'14b and 16b. This elfective pressure difller ential willtend to= movably adjust the regulating block 1111* to-change therelative eccentricity ofthe pumpingchamber bore 17""and the annularring-36 0f the-rotor so that the volume of'fluid passing; through thepumpwill-'- he so regulated as to restore pump inlet pressure topredetermined design value, whereupon the movablevalve spool 81'- willbe returned by the spring- 8210 aneutral'position;

It may'benoted that when the valve spool 81 is} in 'a neutrahposition;the grooves 90;; 92, 96,- 97; 99 and the cooperating lands 101; 102,103, 104; 106 seal-thfe passageways 98 and f-to the respective pressurecontrol chambers 26]) and-27b so that the regulating block 1 1'!) willbe hydraulically locked. Any movement of the if the rotational speedofjth'e pump had varied because a movementof the regulating block 11bwill produce the same efiect on the flow of fluid along'the flow paththrough the-pump-asa speed variation would produce;

The embodiment of "Figure 5 isverysimilar in structure and operation to.the structure described in connection with Figure-4; however, in theembodiment-of Figure 5 operating fluid is conducted from the outlet ofthe pump to the valve, thereby utilizing pump discharge as "a referencepressure instead ofatmospheric pressure.

I'n-the embodimentof Figure 5, the ca'sing20-is provided-with apassageway 110 communicating with the pump outlet 70 as at- 1-11;

The movable value spool'81a'is provided with an annular' peripheralgroove 112 located in spaced relation tothe orifice 88a 'formed' in' theradially inwardly extending rib- 87a andon the upstream side thereof.

An annular groovej92ais formed in the peripheral surface ofthe valvespool 81a and communicates with the inlet passage 77a.on" thedownstreamside of the orifice 88a, through suitable openings 93a.Passage 98a communicates with, the, pressure control chamber 26b andspaced v annulan. grooves 96a and 97a formed in: the bore 790. i

7 An annular groove 99a formed in the cylindrical bore 79a of the inletpassage 77a communicates with the pressure control chamber 27b through apassageway 100a.

Since the orifice 88a is located downstream of the annular groove 112communicating with pump discharge through the passageway 110, a minimumpressure will be provided for conditions where such minimum pressuremight not exist in the pump outlet 70. It should be noted that thisoutlet pressure has no effect on the movable valve spool 81a, but simplypasses through the valve mechanism and acts to move the regulating block11b when called upon to do so by the change in the pressure drop acrossthe orifice 88a. The use of outlet pressure for control operation isonly necessary where the available pressure drop across the orifice 88ais not sufficient to control movement of the block 11b.

Although various minor structural modifications might be suggested bythose versed in the art, it should be understood that I wish to embodywithin the scope of the patent warranted hereon all such modificationsas reasonably and properly come within the scope of my contribution theart.

I claim as my invention:

1. A variable pressure, constant delivery, guided vane pump, comprisinga casing providing a hollow cavity having a pair of flat internal Wallson opposite sides thereof, a rotor providing an annular row ofcircumferentially spaced slots, a corresponding plurality of vanesslidably supported in the respective slots, a floating abutment in saidrotor engaging the inner ends of said vanes, and a regulator blockproviding a cylindrical pumping chamber for receiving said vanes andhaving flat sides slidably supported by said internal walls in saidcasing for movement transversely of the rotor axis to adjust therelative eccentricity of the pumping chamber bore and the rotor, saidcasing having a pair of pressure control cham bers formed therein onopposite sides of said rotor axis, said regulating block having areactive pressure face in each respective pressure control chamber,passageway means forming an inlet on one side of said rotor and anoutlet for said pump on the opposite side of said rotor andcommunicating with said pumping chamber bore, an orifice in saidpassageway means through which all pump operating fluid flows with apressure drop across the orifice, and means communicating variations inthe effective differential of said pressure drop to said reactivepressure faces to regulates the volumetric capacity of said pump inresponse to pressure drop variations across the orifice.

2. A pump as defined in claim 1, wherein said orifice is provided by acontrol valve having a movable valve spool member in said inlet moved indownstream direction by the fluid inlet pressure and being adapted topass rated flow of all of the pumping fluid at a predeterminedquantitative value of pressure drop, and biasing means urging said spoolin upstream direction to a position corresponding to a neutral positionat said predetermined quantitative value of pressure drop, said controlvalve including passages communicating pump operating fluid with saidregulating means and controlled by said valve spool member for thepurposes set forth.

3. A pump as defined in claim 1, said orifice being located in the inletportion of said passageway means, a control valve including passagescommunicating with said regulating means and said inlet and selectivelyopened and closed by a movable valve member, means operativelysubjecting said movable valve member to pump inlet pressure on theupstream side of said orifice and to a pressure less than inlet pressureon the downstream side of said orifice to regulate said member inresponse to the pressure drop across said orifice resulting from theflow of pumping fluid therethrough.

4-. A pump as defined in claim 2 and including passageway meansconducting operating fluid from said pump to said valve for use as areference pressure.

5. A pump as defined in claim 1 wherein said orifice.

is located in the inlet portion of said passageway means.

6. A pump as defined in claim 1 wherein said orifice is located in theoutlet portions of said passageway means.

7. A pump comprising a casing providing a hollow cavity having flatwalls on opposite sides thereof, a rotor providing an annular row ofcircumferentially spaced slots, a corresponding plurality of vanesslidably supported in the respective slots, a regulating block providinga cylindrical pumping chamber bore receiving said vanes and having flatsides slidably supported by said flat walls and said casing for movementtransversely of the rotor axis to adjust the relative eccentricity ofthe pumping chamber bore and the rotor, said casing having a pair ofpressure control chambers formed therein on opposite sides of the rotoraxis, said regulating block having a reactive pressure face in eachrespective pressure control chamber, an inlet in said casingcommunicating with one of said pressure control chambers, a passagewayin said block between said pressure control chambers and having anorifice therein through which all pump operating fluid passes, an inletpassageway in said block between said pressure control chambers and saidpumping chamber bore, an outlet in said casing, and an outlet passagewayin said block communicating said casing outlet with said pumping chamberbore, the restriction provided by said orifice affording a pressuredifferential acting on the respective reactive pressure faces resultingfrom the pressure drop across said orifice to regulate the volumetriccapacity of said pump in response to pressure drop variations acrosssaid orifice.

8. A pump comprising a rotor providing an annular row of slidable vanes,a casing, means providing guideways in said casing, and a regulatingblock providing a cylindrical pumping chamber bore receiving said vanesand having flat sides slidably supported on said guideways in saidcasing for movement transversely of the rotor axis to adjust therelative eccentricity of the pumping chamber bore and the rotor, saidcasing having a pair of pressure control chambers formed therein onopposite sides of said rotor axis, said regulating block having areactive pressure face in each respective pressure control chamber, aninlet in said casing, an inlet passageway in said block communicatingsaid pumping chamber bore with said casing inlet, an outlet passagewayin said block communicating said pumping chamber bore with one of saidpressure control chambers, a passageway in said block between saidpressure control chambers and having an orifice therein through whichall pump operating fluid flows, and an outlet passageway in said casingcommunicating with the other of said pressure control chambers, therestriction provided by said orifice affording a pressure differentialacting on the respective reactive pressure faces resulting from pressuredrop across said orifice to regulate the volumetric capacity of saidpump in response to pressure drop variations across said orifice.

9. A pump, comprising, a guided vane rotor, a casing, and a regulatingblock providing a cylindrical pumping chamber bore receiving said rotor,means providing sliding guideways between said block and said casingslidably supporting said block in said casing for movement transverselyof the rotor axis to adjust the relative eccentricity of the pumpingchamber bore and the rotor, said casing having a pair of pressurecontrol chambers formed therein on opposite sides of the rotor axis,said regulating block having a reactive pressure face in each respectivepressure control chamber, continuous biasing means between saidregulator block and said casing biasing said block in one direction tomaintain minimum eccentricity of said pumping chamber bore and saidrotor, passageway means forming an inlet and an outlet for said pump andcommunicating with said pumping chamber bore, an orifice in saidpassageway means through which all pump fluid passes with a pressuredrop, and means communicating variations in the effective difierentialof .said pressure drop to said reactive pressure faces to regulate thevolumetric capacity of said pump in response to pressure drop variationsby moving said regulator block against the bias of said continuousbiasing means.

10. A pump, comprising, a guided vane rotor, a casing, a regulatingblock providing a cylindrical pumping chamber bore receiving said rotor,and means between said casing and said block providing relativelyslidable support surfaces guiding said block for movement transverselyof the rotor axis to adjust the relative eccentricity of the pumpingchamber bore and the rotor, said casing having a pair of pressurecontrol chambers formed therein, said regulator block having a reactivepressure face in each respective pressure control chamber and located onopposite sides of said rotor axis, a coil spring between said block andsaid casing normally biasing said block in one direction to maintainminimum eccentricity of said pumping control chamber and said rotor,said casing having means providing a fluid flow path therethrough, saidblock having a passageway extending between said pressure controlchambers, an orifice formed in said passageway, and through which allpump fluid passes, additional passageways in said block placing saidpumping chamber bore in communication with one of said pressure controlchambers and with said flow path, and the other of said pressure controlchambers communicating with said fluid flow path, the restrictionprovided by said orifice affording a pressure differential resultingfrom the pressure drop across the orifice and acting on the respectivereactive pressure faces to regulate the volumetric capacity of said pumpin response to pressure drop variations across said orifice by movingsaid regulator block against the continuous biasing means.

11. A pump comprising a guided vane rotor, a casing, a regulator blockproviding a cylindrical pumping chamber bore receiving said rotor andbeing slidably supported in said casing for movement transversely of therotor axis to adjust the relative eccentricity of the pumping chamberbore and the rotor, said casing having a pair of pressure controlchambers formed therein, said regulating block having a reactivepressure face in each respective pressure control chamber and located onopposite sides of said rotor axis, said casing having means providing afluid flow path therethrough, said block having a passageway extendingbetween said pressure control chambers, an orifice formed in saidpassageway and through which all pump fluid passes, additionalpassageways in said block placing said pumping chamber bore incommunication with one of said pressure control chambers and with saidflow path, and other of said pressure control chambers communicatingwith said flow path, the restriction provided by said orifice affordinga pressure differential resulting from the pressure drop across theorifice and acting on the respective reactive pressure faces to regulatethe volumetric capacity of said pump in response to pressure dropvariations across said orifice.

12. A pump comprising, a block having flat sides and providing areactive pressure face on opposite ends thereof, a cylindrical pumpingchamber bore formed in said block between said reactive faces, a hollowcasing having mating fiat internal walls slidably supporting said blockfor movement transversely of the axis of said pumping chamber bore, saidreactive pressure faces on said block being spaced from adjoining wallsof said casing to provide pressure control chambers, a guided vane rotorjournaled in said casing having vanes rotatable in said pumping chamberbore, passageway means forming an inlet and an outlet for said pump andcommunicating with said pumping chamber bore, and flow responsive meanscommunicating pressure to said pressure control chambers as a functionof the flow rate of pump operating fluid for subjecting said reactivepressure faces to a flow differential to regulate the relativeeccentricity of said rotor and said bore to regulate the capacity ofsaid pump, comprising an orifice in said passageway means, and meansoperatively subjecting one of said pressure control chambers to thepressure on the upstream side of said orifice and the other of saidpressure control chambers to the pressure on the downstream side of saidorifice, thereby to regulate the capacity of said pump in response tothe pressure drop variations across said orifice.

13. A pump comprising a block having flat sides and providing a reactivepressure face on opposite ends thereof, a cylindrical pumping chamberbore formed in said block between said reactive faces, a hollow casinghaving flat internal walls mating with said flat sides of said block andslidably supporting said block for movement transversely of the axis ofsaid pumping chamber bore, said reactive pressure faces on said blockbeing spaced from adjoining walls of said casing to provide a pair ofpres sure con-trol chambers, a guided vane rotor journaled in saidcasing having vanes rotatable in said pumping chamber bore, passagewaymeans forming an inlet and an outlet for said pump and communicatingwith said pumping chamber bore, said casing having means providing afluid flow path therethrough, said block having a passageway extendingbetween said pressure control chambers, an orifice formed in saidpassageway through which all pump operating fluid passes, additionalpassageways in said block placing said pumping chamber bore incommunication with one of said pressure control chambers and with saidflow path, and the other of said pressure control chambers communicatingwith said flow path, the restriction provided by said orifice affordinga pressure differential acting on the respective reactive pressure facesto regulate the volumetric capacity of said pump in response to pressuredrop variations across said orifice.

References Cited in the file of this patent UNITED STATES PATENTS2,238,061 Kendrick Apr. 15, 1941 2,387,761 Kendrick Oct. 30, 19452,451,279 De Lancey Oct. 12, 1948 2,600,632 French June 17, 19522,600,633 French June 17, 1952 2,635,551 De Lancey Apr. 21, 19532,678,607 Hufferd et al.- May 18, 1954

